1. Field of the Invention
The present invention relates to a particular apparatus and method of manufacturing actuators that are suitable for use on aerosol dispensers or pumping assemblies. More specifically related to an actuator assembly that resembles the conventional types which are effective in preventing or reducing partial or total clogging through the introduction of air causing the drying or hardening of the product being dispensed within the flow channels and discharge orifice of the actuator assembly between the atomization stages or over intervals of usage.
2. Description of the Related Art
Actuator assemblies that fit on top of aerosol containers or that are used as part of a pumping system have been used for many years to dispense liquid or product under pressure through an orifice or opening. Often, the liquid or product is atomized via a (MBU) mechanical breakup means within the actuator assembly before it exits out the orifice as a fine spray using a specially configured nozzle or other mechanism. While these devices typically work well initially, they typically become partially or fully clogged as the product being dispensed dries and hardens in various flow channels and in the discharge orifice. Many of these other actuators rely on mechanical force, such as a spring or other mechanism, to open an orifice and flow channels for dispensing by withdrawing a probe or plug from the orifice and then closing the orifice after dispensing the product by moving the probe or plug back towards or into the orifice.
By way of example, U.S. Pat. No. 5,198,774 of Lund et al, discloses a combined lock and anti-clog actuator. The actuator is adjustable between a locked and an unlocked position. The locked position cooperates with an anti-clog member, which has a nozzle seal for inhibiting the clogging of the product within.
U.S. Pat. No. 5,894,964 of Barnes et al, discloses an inner actuator chamber arranged in a way designed to minimize blockage of the actuator.
U.S. Pat. No. 5,480,095 of Stevenson et al, shows an actuator that attenuates the accumulation of solidified sprayed fluid.
U.S. Pat. No. 5,687,877 of Smolen, Jr., discloses a pump dispenser with a check valve that moves forward during the pressure stroke and than closes and pulls liquid back during the suction stroke, minimizing blockage.
U.S. Pat. No. 5,560,544 of Merritt et al, discloses an anti-clogging atomizer nozzle. U.S. Pat. No. 5,358,149 of O""Neill discloses an anti-clogging means similar to U.S. Pat. No. 5,687,877 of Smolen, Jr.
U.S. Pat. No. 4,982,900 of Blake discloses a trigger sprayer with several nose piece valve configurations.
U.S. Pat. No. 5,855,322 of Py discloses a one-way valve system that utilizes a swirl chamber with radially deformed, expandable outlet flexing valving as part of a pouched reservoir system, as an inclusive assembly.
Despite the efforts of such devices as shown in the forgoing patents, there remains a need for an anti-clogging actuator that can perform a rapid positive shut off. Specifically, a product that can prevent clogging from occurring by effecting a rapid shut off; that would afford an effective shut off method to prevent product build up behind the orifice at sealing surfaces and within flow channels; and that would create a positive shut off to reduce dribbling or seeping under low pressure would be most desirable, especially if the part count remains the same as with conventional actuators while employing a method of unitary overmolding of two separate materials, accomplishing the same desired equivalent features.
It is the object of the present invention to provide a method for the apparatus, that can be manufactured economically while maintaining all the features of non-clogging and positive shutoff within an actuator that does not increase in a total number of parts that are presently available. This actuator assembly will still isolate fluid within the MBU (mechanical breakup channels and orifice), preventing air from migrating back through the same.
It is a related object of the present invention to provide a non-clogging actuator assembly that has two diaphragms in tandem with a mechanical breakup between them, the in tandem diaphragms also provide double one-way valving with flexible movement to afford mechanical breakup and positive shutoff features that respond to a predetermined threshold pressure supplied by a number of systems in present use.
It is another object of the present invention to provide a means that enables the elimination of the pump outlet valve requirements when new concepts need economic relief to manufacture competitively for same uses and still work with existing pumps and dispensers that may or can utilize those needed features.
It is another object of the present invention to provide a non-clogging actuator that has a positive shutoff to prevent or reduce dribbling or seeping.
It is another object of the present invention to provide a non-clogging actuator with or without a positive shutoff feature, that is commercially advantageous by having no increase in overall part count greater than the conventional two piece systems currently being used, while easily being molded without complex actions, and adaptable for use in existing and future aerosol systems; and which lends itself to a variety of assembly modes and an assembly sequence that allows for subassembly pre-testing before final assembly.
Additional objects, advantages, and novel features of the invention will be set forth in part in the description that follows, and in part will become apparent to those skilled in the art upon examination of the following or may be learned by the practice of the invention. The objects and advantages may be realized and attained by means of the instrumentalities and in combinations particularly pointed out in the appended claims.
To achieve the foregoing and other objects and in accordance with the purposes of the present invention, as embodied and broadly described herein, an actuator assembly is provided, that addresses the above discussed clogging and pressure decreasing at end of stroke or duration of an aerosol spray system, problems. The actuator assembly according to this invention includes a overmolded and bonded laminate structure that is fabricated through a two stage overmold process producing an inserted unitary part which is of two different materials and two different durometers ie densities, that is assembled conventionally into a standard type actuator housing having a receiving pocket with a center post that has a face configuration that interfaces with the overmoled unit, and same post having a frustrum shoulder a distance down from its face that also interfaces with the overmolded unit, as the dual in tandem diaphragms-valves with MBU configuration sandwiched in between them allows each to flex in proper order, under pre-determined threshold pressures supplied by a system providing them. According to this invention, a flexible diaphragm flexes away from the first and second mating seal surfaces when product under pressure flows into contact with these flexible in tandem diaphragms. These in tandem diaphragms then resiliently springs back into abutting, biased sealing contact, shutting off the mating surfaces providing the positive shutoff feature desired. Preferably, the apparatus flexes away from the two mating surfaces at a predetermined minimum pressure, which can be set at various thresholds for various needed product categories, thereby controlling the dispensing of those products (i.e., the product is dispensed in a fairly constant pattern and then shut off rather than being very strong at the beginning of the spraying process and then dribbling out at the end or under low pressure operations). Those skilled in the art will recognize that any minimum predetermined pressure required to activate the disclosed assembly will vary with the type material and the geometry selected for the individual components.
Other features and advantages of the invention will become clear from the following detailed Description and drawings of particular embodiments of the actuator system and method and associated combinations and features of the present invention.